Aspects of the invention described in the present application are described in Disclosure Document No. 538798 titled “Integrated Computer Input Device,” received by the United States Patent and Trademark Office on Sep. 22, 2003.
The present invention relates to computer keyboards and in particular to an improved keyboard which reallocates mouse functions to the sides of the keyboard and provides palm support to reduce the occurrence of carpal tunnel injury.
Modern society has replaced many of the physically demanding and often dangerous tasks common in the past, with relatively safe and much less physically demanding office jobs. While many serious injuries and possibly fatalities are now avoided, certain tasks associated with office jobs have resulted in a new types of injury, for example, repetitive motion injuries and repetitive strain injuries.
A common form of repetitive strain injury is Carpal Tunnel Syndrome (CTS). CTS is a condition affecting the median nerve of the wrist. The median nerve passes through the carpal tunnel and CTS results from the median nerve being compressed within the carpal tunnel. Such compression of the median nerve may result in pain, numbness, and/or tingling in the fingers, hand, or wrist. The median nerve provides most of the feeling to the hand and in particular to the thumb, the index finger, the middle fingers, the thumb half of the palm, and the outer side of the hand.
CTS results in more than 2 million visits to physician's offices each year and is one of the most common job related injuries. Over one quarter of a million carpal tunnel surgeries are performed each year in the United States, and 47% of the surgeries are considered to be work-related. The Bureau of Labor Statistics found that in 1994, CTS accounted for 1.7% of workplace related injuries causing work loss. Nearly half of the CTS cases result in 31 days or more work loss, and if not treated properly, CTS may cause irreversible nerve damage and permanent disability.
Although disagreement exists as to the cause of CTS, some physicians believe that an unnatural bending and prolonged over use of the wrist inflames a protective layer over tendons in the wrist. The protective layer, called the synovial sheath, may swell and thereby place pressure on the median nerve in the carpal tunnel. The long-term use of a computer is an often cited example of such unnatural bending and prolonged over use of the wrist. Specifically, repetitive use of a computer mouse may result in asymmetrical tension across the upper back (e.g., the trapezium major and minor rhomboids, latissimus dorsi, etc.) caused by repeated movement of the shoulder and the arm controlling the mouse and by the position of the user's wrists while using the mouse.